National Semiconductor LMX9838, Руководство пользователя

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19.0 Soldering
The LMX9838 bumps are designed to melt as part of the Sur-
face Mount Assembly (SMA) process. In order to ensure
reflow of all solder bumps and maximum solder joint reliability
while minimizing damage to the package, recommended re-
flow profiles should be used.
Table 28, Table 29 and Figure 14 provide the soldering details
required to properly solder the LMX9838 to standard PCBs.
The illustration serves only as a guide and National is not li-
able if a selected profile does not work.
See IPC/JEDEC J-STD-020C, July 2004 for more informa-
tion.
TABLE 28. Soldering Details
Parameter Value
PCB Land Pad Diameter 13 mil
PCB Solder Mask Opening 19 mil
PCB Finish (HASL details) Defined by customer or manufacturing facility
Stencil Aperture 17 mil
Stencil Thickness 5 mil
Solder Paste Used Defined by customer or manufacturing facility
Flux Cleaning Process Defined by customer or manufacturing facility
Reflow Profiles See Figure 14
TABLE 29. Classification Reflow Profiles (Note 27), (Note 28)
Profile Feature NOPB Assembly
Average Ramp-Up Rate (Ts
MAX
to Tp) 3°C/second maximum
Preheat:
Temperature Min (Ts
MIN
)
Temperature Max (Ts
MAX
)
Time (ts
MIN
to ts
MAX
)
150°C
200°C
60 – 180 seconds
Time maintained above:
Temperature (T
L
)
Time (
tL
)
217°C
60 – 150 seconds
Peak/Classification Temperature (Tp) 250 + 0°C
Time within 5°C of actual Peak Temperature (tp) 20 – 40 seconds
Ramp-Down Rate 6°C/second maximum
Time 25 °C to Peak Temperature 8 minutes maximum
Reflow Profiles See Figure 14
Note 27:
See IPC/JEDEC J-STD-020C, July 2004.
Note 28: All temperatures refer to the top side of the package, measured on the package body surface.
30027912
FIGURE 14. Typical Reflow Profiles
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LMX9838